According to Jeff Bezos, it's a hardware button, and various sources seem to agree from the teardowns
A forum post at the EEVblog forums quotes a video featuring Jeff Bezos, the founder of Amazon:
In this video about Jeff Bezos being interviewed by Walter Isaacson at around the 6 min mark, Bezos claims the mute button on the Amazon Echo is physically ...
The Google Home and Amazon Echo use microphone arrays to enhance 'far-field recognition' (i.e. recognising your voice from a reasonable distance with good accuracy).
The Echo uses a 7-microphone array (image from iFixit, with the microphones in green) and the Google Home uses a 2-mic array (iFixit; in yellow).
Amazon's 7-Mic Array is open for developers ...
There are currently just two Bluetooth profiles supported.
Advanced Audio Distribution Profile (A2DP)
This profile allows you to stream audio from your mobile device (such as a phone or tablet) to Echo.
Audio / Video Remote Control Profile (AVRCP)
This profile allows you to use hands-free voice control when a mobile device is connected to ...
Aurora0001's great answer got me doing some more research and I found some really good information on a lot of mic arrays, including benchmarks.
Seeed ReSpeaker Mic Array
Conexant 4-Mic Development Kit
(Tonor Stereo Condenser Microphone)
medium.com did some awesome benchmarking on these. For ...
The button feels like a momentary push switch and I'm 99% certain that the mute state is reset on a reboot.
With both of these in mind I would suggest that it's a software controlled mute rather than physically disconnecting the mic.
I agree with @hardillb's assessment: it's a software button. I have several basic reasons for believing so:
The mute button turns on a red ring light. While it would be possible to do this with a hardware button, it makes more sense logistically to do this with a software button.
If I'm not mistaken, the mute button controls the speakers as well as the ...
As @MaxDZ8 says, your question is very broad, but I'd like to encourage you, and this is something I'm also interested in.
You should start small, perhaps with a simple system.
You've mentioned an IP-camera, and the Pi 3 can certainly do that, for example:
Build a Raspberry Pi Webcam Server in Minutes
(see Setting up outside External Access)
Regarding your ...